[WebAssembly] Fixed Disassembler ignoring endian swap on big endian.

[aardappel]

Summary

This fixes: https://bugs.llvm.org/show_bug.cgi?id=40620

[aheejin]

test/MC/Disassembler/WebAssembly/wasm.txt

37 ↗

(On Diff #185901)

We can delete the comment now :)

[aardappel]

Removed old comment.

llvm/trunk/lib/Target/WebAssembly/Disassembler/WebAssemblyDisassembler.cpp

static bool parseLEBImmediate(MCInst &MI, uint64_t &Size,
   MI.addOperand(MCOperand::createImm(Val));
   return true;
 }
 
 template <typename T>
 bool parseImmediate(MCInst &MI, uint64_t &Size, ArrayRef<uint8_t> Bytes) {
   if (Size + sizeof(T) > Bytes.size())
     return false;
-  T Val;
-  memcpy(&Val, Bytes.data() + Size, sizeof(T));
-  support::endian::byte_swap<T, support::endianness::little>(Val);
+  T Val = support::endian::read<T, support::endianness::little, alignof(T)>(
+      Bytes.data() + Size);
   Size += sizeof(T);
   if (std::is_floating_point<T>::value) {
     MI.addOperand(MCOperand::createFPImm(static_cast<double>(Val)));
   } else {
     MI.addOperand(MCOperand::createImm(static_cast<int64_t>(Val)));
   }
   return true;
 }

llvm/trunk/test/MC/Disassembler/WebAssembly/wasm.txt

 
 # CHECK: local.get 128
 0x20 0x80 0x01
 
 # Prefix byte example:
 # CHECK: i64.trunc_sat_f64_u
 0xFC 0x07
 
-# FIXME Disabled temporarily due to failures in clang-ppc64be-linux and
-# clang-s390x-linux bots
-# C HECK: v128.const 50462976, 117835012, 185207048, 252579084
+# CHECK: v128.const 50462976, 117835012, 185207048, 252579084
 0xFD 0x02 0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08 0x09 0x0A 0x0B 0x0C 0x0D 0x0E 0x0F
 
 # CHECK: v8x16.shuffle 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
 0xFD 0x03 0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08 0x09 0x0A 0x0B 0x0C 0x0D 0x0E 0x0F
 
 # Check LEB128 encoding of SIMD instructions
 # CHECK: i64x2.all_true
 0xFD 0x86 0x01